Inferential role semantics (also conceptual role semantics, functional role semantics, procedural semantics, inferentialism) is an approach to the theory of meaning that identifies the meaning of an expression with its relationship to other expressions, typically its inferential relations with other expressions. Proponents include Robert Brandom, Gilbert Harman, Paul Horwich, and Ned Block. Inferential role semantics originated in the later work of Ludwig Wittgenstein.
Inferential role semantics is sometimes contrasted to truth-conditional semantics. Jerry Fodor coined the term "inferential role semantics" in order to criticise it as a holistic (i.e. essentially non-compositional) approach to the theory of meaning.
The approach is related to accounts of proof-theoretic semantics in the semantics of logic which associate meaning with the reasoning process.